Stop-motion thread-frame.



F. CRAWFORD, Sm. STOP MOTION THREAD FRAME.

APPLICATION FILED APR. 9. l917- Patented July 23, 1918.

UNITED STATES PATENT OFFICE.

FRANK CRAWFORD, SR., OF NEW BRUNSWICK, NEW JERSEY, ASSIGNOR TO THE CRAW- FORD MANUFACTURING COMPANY, OF NEW BRUNSWICK, NEW JERSEY, A CORPO- RATION OF NEW JERSEY.

STOP-MOTION THREAD-FRAME.

Specification of Letters Patent.

Patented July 23, 1918.

. Application filed April 9, 1917. Serial No. 160,737.

To all whom it ma concern Sr., a citizen of the United States, and a resident of New Brunswick, county of Middlesex, State of New Jersey, have in vented certain Improvements in Stop-M0- tion Thread-Frames, of which the following is a specification.

This invention relates to certain improvements in a thread guide for stop motions for knitting machines, such as shown in the patent. granted to me on the 22nd day of Februar 1916, No. 1,172,950.

The 0 ject of my present invention is to prevent the accidental operation of the stop motion when very light yarns are used. In some instances, the tension is so slight that the yarn will allow the arm to move to such a position as to release the stop mechanism and stop the machine.

In the accompanying drawings v Figure 1, is sufficient of a head of a stop motion for knitting machines to illustrate my invention;

Fig. 2, is a section view on the line 2-2, Fig. 1;

Fig.3, is a sectional view on the line 3-3,

Fig 1;

ig. 4, is a detached view of my improved guide plate; and

Fig. 5, is a view of a modification of the plate.

1 is a casing. 2 is a bracket projecting from the casing; this bracket carries the trip mechanism of the stop motion. In the easing is the mechanism for regulating the tension devices, which control the hook mechanism which is actuated when there is a knot in the thread. In the lower portion of the casing is the mechanism which is controlled by the trip device when the thread is broken. This action of the mechanism stops the knitting machine. The de tail of this mechanism is clearly shown in the patent granted to me on the 12th day of December 1893, No. 510,839.

Depending from-the bracket is a frame 3 made in this instance of wire, bent as shown, and having three bars 4, 5 and 6, spaced a iven distance apart, as clearly illustrated 1n the drawing. 7 is a rock shaft adapted to suitable bearings and connected atits outer end with a lever 8 forked at 9 to receive the thread as, which passes from the forked portion 9 through a thread guide 10 and back of the bars 4, 5 and 6. rock shaft connected with the internal mechanism of the stop motion in the casing 1 and has an arm 12 terminating in two bars 13 which rest in the space between the bars 4, 5 and 6 of the frame 3. Usually, the thread 00 comes in direct contact with the narrow bars 4, 5 and 6 so that when the thread is drawn, as illustrated by dotted lines, Fig. 2, there is very little friction. This construction is adapted to the usual threads used in knitting but is not adapted to the very fine threads employed now in many instances.

In order to increase the friction, I provide a guide plate 14, shown clearly in Fig. 4, which has flat bars 15, 16 and 17, resting directly back of the bars 4, 5 and 6, respectively. These bars 15, 16 and 17 are rounded at each edge, as clearly shown in "Fig. 2, so as to present a smooth surface over which the thread passes. By making the bars in this manner, there is 'suilicient friction to prevent the drawing of the thread over the bars and, consequently, when a very light thread is used there is no tendency to trip the delicate stop motion mechanism, unless a thread breaks.

I preferably make the guide plate so that it can be readily attached to or detached from the frame 3 and I provide spring clips 18 at each end which engage the vertical bars 19 of the frame 3. By this means, the guide plate can be detached from the frame when comparatively coarse yarn is being used and can be readily attached when fine am is used. Moreover, stop motionsnow in different factories can beequipped with this attachment.

In Fig. 5 I have illustrated a modification of the invention in which the guide frame 14 has two comparatively short fingers and one long finger 16*, which has a clamp 16 at the end arranged to engage 11 is a.

a frame having cross bars on one sideof which the thread extends; a detachable guide plate secured to the frame and having a broad surface at the bars of said frame; and a pivoted arm having bars located between the bars of the frame and arranged so that each thread passes over the broad surface of the guide plate and around the bars of the pivoted arm.

2. The combination in a stop motion, of a bracket; a frame depending from the bracket and having cross bars; a detachable guide plate mounted on the bars of the frame and having broad bearing faces for the thread; a pivoted arm arranged to actuate the trip mechanism for the stop motion and having bars located between the bars of the frame so that the thread passes alternately over the broad bearing face of the guide and the bars of the pivoted arm.

3. The combination in a stop motion for knitting machines, of a casing containing the trip-mechanism; a bracket projecting from the casing; a frame depending from the bracket and having three bars; a shaft projecting from the casing; an arm carried by the shaft and having bars located between the bars of the frame, the thread being engaged by the two sets of bars; and a guide plate mounted on the frame and having bars alining with the bars of the frame, the bars of the plate being broad and curved at each edge and forming an increased frictional surface.

4. The combination in a stop motion, of a frame having cross bars back of which a thread'extends; a shaft having a pivoted arm and having bars located between the bars of the frame and in front of which the thread extends so as to hold the arm out of action; a guide plate located back of the frame and having fiat portions extending back of the bars of the frame, said plate having spring clips at each edge arranged to engage the frame and to hold the plate in a fixed position on the frame.

5. The combination in a stopmotion, of a frame having a series of bars spaced apart; a trip actuating arm having bars alternating with the bars of the frame; and a detachable guide plate secured to one of said elements and having a broad surface at the bars forming extended surfaces for the thread so as to prevent the accidental operation of the stop motion when light yarns are used.

In witness whereof I afiix my signature.

FRANK CRAWFORD, SR. 

